Mazda pioneer in starter technology!! Smart Idle Stop System
Don't know if you guys have seen this before.. but it looks really good idea and could be in the next version of the mazda 3.
Source:
http://www.wheels.ca/article/32454
Mazda pioneer in starter technology
Gerry Malloy
Oct 27, 2007
The introduction of the electric self-starter on the 1912 Cadillac was a turning point in automotive history. It circumvented the need to hand-crank the internal combustion engine to start it, thus eliminating perhaps its biggest drawback and paving the way for it to become the dominant automotive powerplant for the rest of the century – and beyond.
Ironically, a new technology developed by Mazda and revealed this week at its Hiroshima engineering centre, in advance of the Tokyo Motor Show, is almost a direct reversal of that achievement.
It makes use of the characteristic that made hand-cranking engines so dangerous, to eliminate the need for a high-powered starter motor.
And while its impact is unlikely to be as dramatic as the original self-starter, it could prove to be highly significant.
The technology is called SISS, for Smart Idle Stop System – the ISS referring to a vehicle's ability to automatically shut off its engine when it stops moving, and instantly restart it when the brake is released or the accelerator pressed.
Stop-start technology has been previously discussed in this column, noting that it plays a major role in the fuel savings realized by most hybrid vehicles. But one of the limitations of the system is that it requires a high-powered electric motor and battery pack to provide instant restarts, thus effectively limiting the technology to hybrids.
At least that was the case until now.
Mazda's SISS system has no such need. Which is why the first S in its acronym stands for "smart."
Its operation makes use of the engine characteristic that old-timers called "kickback." If you didn't time the release of the hand crank just right, the engine could kick it back and, in an instant, break your arm.
With SISS, when an engine is shut down, electronic controls ensure that it stops with all four pistons, of a four-cylinder engine, lined up exactly half way between top- and bottom-dead centre.
When the signal to automatically restart is received, a squirt of fuel is injected into one cylinder, via Mazda's DISI direct-injection system, and its spark plug is fired, causing ignition in that cylinder alone that pushes its piston down, rotating the engine slightly backward.
At that point, as other pistons are pushed up into compression, the normal fuel-injection and ignition systems take over, igniting the mixture in those cylinders and starting the engine in the forward direction – without the aid of any electric starter.
Not only that, the system restarts the engine in less time than it takes with an electric starter, according to Mazda, thus making its operation even more seamless – a point subjectively verified by a demonstration drive.
According to tests conducted to Japan's emissions/fuel-consumption testing procedure, SISS reduces consumption by approximately 10 per cent, Mazda says, with virtually no extra cost in hardware, and no additional weight for beefed up starter motors or batteries.
And it opens the door to applying automatic start-stop systems to non-hybrid vehicles, which has huge potential for benefit.
With automakers scrambling to make tenths-of-a per cent reductions in fuel consumption, the prospects of making a 10 per cent reduction almost for free qualifies as a major breakthrough.
Mazda has not yet announced production plans for the system, but given its potential impact, and the fact the company is making the technology public, it is almost certainly destined for near-term introduction.
It is equally likely that other manufacturers will follow suit with similar technology, if not a licenced version of Mazda's system.
And the world will be a better place for it.
1. The system injects a small amount of fuel into the cylinder whose piston is part-way through its compression stroke and ignites it, causing the engine to run slightly in reverse.
2. The system then injects fuel into the cylinder that has begun to undergo compression owing to the engine’s reverse operation.
3. Finally, the system ignites the latterly injected fuel, causing powerful expansion that drives the engine in the forward direction, thereby starting the engine.
Some more info here as well http://www.motortrend.com/features/a...10_tokyo_tech/
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Originally Posted by stevenlung
